1. Field of the Invention
This invention relates to excavators, such as power shovels used in mining; and more particularly to operator controls for operating the excavator.
2. Description of the Related Art
A typical mining power shovel includes a turntable mounted on a crawler assembly and the turntable supports an A-frame and a body that houses electrical controls and mechanical components. A boom, extending from the turntable, has an upper end supported by the A-frame and pivotally supporting a dipper handle that pivots in a vertical plane. A dipper, fixed to a distal end of the dipper handle, is raised and lowered by a hoist cable which extends from a drum in the body, over a sheave at the top of the boom, and down to a padlock on the dipper. Winding and unwinding the hoist cable on the drum moves the dipper vertically. A crowd assembly extends and retracts the dipper handle to provide the horizontal component, or crowd, of the dipper's movement. The dipper has a bottom door held closed by a latch, which is operated from the body by a cable. Releasing the latch allows to door to open by gravity, thereby dumping contents of the dipper. Moving the dipper toward the ground causes the door to swing closed and engage the latch.
Operation of the power shovel is controlled from a cab on the body. The shovel operator sits in a seat in the cab and manipulates controls that activate the different functions on the power shovel. A control panel adjacent to the seat contains manual control devices and indicators associated with functions of the power shovel.
During excavation, the power shovel digs material from the earth and deposits the material into dump trucks that drive along either side of the shovel. Thus the power shovel swings back an forth between the dig site and the location of the dump trucks. As the mining shovel swings, the operator looks out a window of the cab in the direction in which the shovel is moving. At the same time the operator also has to observe operating parameters of the power shovel that are displayed on an indicator panel. For example, some of the indicators designate the amount of material in the dipper and the amount of material that has been deposited in the dump truck being loaded presently.
Depending on whether the power shovel is swinging to the right or left between the dig site and the dump truck, the operator is looking in that direction. However, the control devices and operating parameter indicators heretofore were located in fixed positions on the control panel and not always in the same direction in which the operator was looking. Therefore in order to observe those indicators or operate a control device, the operator often had to turn away from the direction that the power shovel was swinging. This repetitive turning motion not only was tiresome, it caused the operator to look away from the direction of the swing. Regardless of their position in the cab, the indicators and control devices on the control panel never were located optimally for both swing directions.